Common Problems

The most common problem we hear is that the cylinder axis changes when the Cross Cylinders are rotated into position or conversely that the Cross Cylinder Turret moves when the Cylinder Axis is adjusted.

These are both caused by the same problem – lack of maintenance. Old grease mixes with dust & dirt to bind up this mechanism. As a part of every Tek-Net Preventive Maintenance, the Cross Cylinder Turret is disassembled and the grease and dirt are removed. Once everything is cleaned up we assemble it and set the proper axis.

Other problems which crop up an a regular basis are:

The cylinder power scale does not move when I change lenses.

This happens when the teeth on the cylinder power scale wear down and eventually stop making contact. This repair is fairly involved because the cylinder lenses must be removed from the housing to replace the scale. Care must be taken to ensure that the lenses are put back exactly on axis

When I dial up “0” cylinder, there is a lens in the apeture.

Most of today’s Refractors give cylinder readings up to 6 diopters. This is done by superimposing 1 lens bank above another. After time, the assemblies which drive these lens banks can loosen up or wear down and a lens can slip past it’s stop and cause the dial to go out of sequence. The cylinder back must be taken off and the lens banks synchronized again to give the proper reading

The Auxillary Dial Scale does not move when I change lenses

The knob which rotates the Auxillary Dial and the scale which tell you where the dial is are 2 actually parts which are pressed together. The scale can be dislodged if pressed and the 2 parts separate.

The patient cannot see the chart clearly

Again, lack of regular maintenance is to blame. Even though very few doctors allow smoking in their offices, there are a myriad of factors conspiring to cloud up your lenses. Believe it or not, the wrong instrument cover can add to this. The old clear plastic covers actually “out-gas” and cause a film to develop on the lenses (similar to the film that forms on the inside of your windshield) We recommend using only nylon covers.

Add residue from makeup and mascara, tears, the occasional chocolate covered child’s finger and dust in the air to this and it does not take long to cloud up your clean lenses. Again, regular Preventive Maintenance is the only solution to this.

If you decide to take matters into you own hands, all I can say is good luck. In the 20 plus years I have been in this business that hardest job I have encountered is teaching someone how to properly clean a lens!

If you run into a problem not listed above, contact me and I will add it to the list.